Differential-gear pulley-block.



No. 708,!52. Patented sepi'. 2 I902. I n. LAVERY.

I DIFFERENTIAL GEAR PULLEY BLOCK.

7 (Application filed Mar. 29. 19014) (No Model.) 3 Sheeis8h6et I.

No. 7ns,|s- 2. Patented Sept. 2, I902.

- n. {.AVERY.

DIFFERENTIAL GEAR PULLEY BLOCK.

, (Application filed Mar. 29, 1901.) (No Model.)

ms N'onms PETERS ca, mom-Luna" WASHINGTON, 0, c4

No. 708152 Patented Sept-2, I902.

1 R. LAVERY.

DIFFERENTIAL GEAR PULLEY BL'ocK.

' (Application filed Mar. 29, 1901.) v

(No Model.) 3 Sheis-8heet 3 U T D STATES- PATENT OFFICE.

RICHARD LAVERY, OF BOSTON, MASSACHUSETTS.

DIFFERENTIAL-G EAR PU LLEY-BLOCK.

SPECIFICATION forming part of Letters Patent No. 708,1 52, dated September 2, 1902.

Application filed March 29, 1901. Serial No. 53,448. (No model.)

To all whom, it may concern: Be it known that I, RICHARD LAVERY, a ci tizen of the United States, residing in the city of Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Differential Gear Pulley-Blocks, whereof the following is a specification. v

My invention relates to improvements on that class of gear devices set forth and claimed by me in Letters Patent of the United States No. 281,195, of July 10, 1883; No. 286,206, of October 9, 1883; No. 298,697, of May 13,1884, and No. 402,601, of May 7, 1889, all of which were heretofore granted to me.

The object of my invention hereinbelow set forth is the production of a differentialgear pulley-block that shall be adapted to be used not only for the relatively slow lifting and lowering of heavy loads through the operation of the differential-gear power, but

also for the relatively rapid lifting and lowering of loads,whether light'or heavy, through the action of direct simple-pulley power independent of the differential-gear power.

My invention consists, primarily, in means adapted to automatically throw 0d the differential power in differentialpower pulleyblocks and allow the use of the lifting sheave or sheaves as a direct simple pulley, such antomatic action being accomplished without any act on the part of the operator except that of hauling on the fall end of the load-' chain.

My invention consists, preferably, in means I whereby the differential-gear operating-wheelof my aforesaid Letters Patent is adapted to be thrown out of action as a source of difierential power whenever the lifting sheave or sheaves may be required for rapid use as a direct-power simple pulley-block. I thus greatly facilitate the manipulation of loads that are much lighter than the maximum load for the diiferential power and "also facilitate the operation of overhauling the chain in the handling of any load.

My invention further consists in the com-f bination, with the foregoing, of a proper ratchet or clutch device adapted to hold the suspended load at any point while the block is in use as a simple pulley.

' My invention further consists in the comin the combination,with the foregoing, of such a form of notches in the ratchet or clutch aforesaid that the ratchet or clutch cannot be released by direct pull upon the pawl engaging such notches unless a slight reverse rotation of the ratchet isfir st caused by braking the lifting-sheave and simultaneously operating the diiferential power.

Allof the foregoing features of my invention are hereinafter set forth in a particular and preferable form; but I do not limit my invention to such special form.

In the accompany drawings, forming a part of this specification, Figure 1 is aside elevation of the tackle-block, showing the differential-gear operating-Wheel with its endless chain and the ratchet-and-pawl device and also the lever of the band-brake for the lifting-sheave beyond the operatingwheel. Fig.2 is an elevation from the opposite side of the block, showing the lifting-sheave with its load-chain and the band-brake as applied to a brake-wheel integral with the liftingsheave. Fig. 3 is an edge view of one of the differential gears carried by the operatingwheel, and Figs. 4 and 5 are views of respectively opposite sides of the said gear. Fig. 6 is a vertical section of the block on the lines 6 6 of both Fig.1 and Fig. 2. Fig. 7 is an enlarged detail side elevation of the ratchet and pawl shown in Figs. 1 and 6; and Fig. 8 is a merely diagrammatic View to show the direction in which the lifting-chain is reeved through the block, the operatingwheel and the brake-wheel being omitted for clearness, and the brake-lever and ratchet and pawl beingindicatedin dotted lines. Fig. 9 is a perspective view of the com plete mechanism.

Like letters of reference indicate like parts in alllthe figures, and all the direction arrows' indicate the direction of movement of the parts when the differential mechanism is in operation in the act of hoisting a load.

A is the operating-wheel, carrying the differential gears B B B B and actuatedby the endless chain 0 O, whereof only the upper loop is shown, the said chain passing through the chain-guides D D. The respectively different gears E E of each differential gearwheel B mesh, respectively, with separate gears F F, that are rotatable on the shaft G. The gear'F is secured to or integral with the ratchet II and forms the hub thereof. Additional plain sheaves J J whose peripheries are not provided with pockets to engage the individual links of the chain are supplied to cooperate with the pocketed sheave I when it may be necessary to multiply the lifting powerof the latter. The ratchet His engaged by the pawl K, pivoted at L, and having the lever M and counterweight N. The liftingsheave I carries the load-chain O, which may also he reeved through the unpocketed sheaves J J to multiply the lifting power at the expense of speed. Secured to or integral with the liftingsheave I is the brake-bearing wheel P,-adapted to furnish a frictional bearing for the band-brake Q, operated by the lever R and secured to the said lever by the pin and bolt S. The ratchet H is provided with lock-notches T T, that prevent the disengagement of the pawl K until the ratchet has been caused to rotate slightly in the direction reverse to that in which the said ratchet normally bears against the said pawl. The cord V controls the pawl-lever M, and the cord W controls the brake-lever R.

When the endless hand-chain O C is used to actuate the differential-gear operatingwheel A, the ratchet and pawl hold the center gear F in a fixed position, and the said gear F constitutes the fulcrum by means of which the differential gears rotate the other center gear F, and so actuate the lifting-sheave. Then the fall end of'the load-chain O O is pulled upon directly, the ratchet will rotate in the reverse or release direction, and the lifting-sheaves I J J will thus become a direct-power simple pulley, with the additional feature that the ratchet and pawl allow the load to be freely held suspended at any point. The pawl may at any time be released from the ratchet by holding the lifting-sheave with the band-brake and simultaneously turning the differential-gear operating-wheel in the direction of lowering until the reverse motion of the ratchet withdraws the lock-notch T from the end of the pawl, and thus allows the lever M to be pulled down. When the lifting-sheave is so held by the band-brake, the center gear F becomes the fulcrum by means of which the differential gears cause the said reverse rotation of the ratchet. Whenever the lever M is pulled down and the pawl thus held away from contact with the ratchet K, the load may be lowered by using the liftingsheaves I J J and their load-chain O O as a simple block and tackle and controlling the main or pocketed sheave I by means of the band-brake. Likewise the overhauling of the load-chain is facilitated.

Having thus set forth myinvention, I new claim-- 1. In a pulley-block, in combination, a differential gear operating-wheel, a lifting sheave or set of sheaves, and means adapted to automatically throw off the differential power and allow the use of the lifting sheave or sheaves as a direct simple pulley, substantially as specified.

2. In a pulley-block, in combination, a differential gear operatingwheel, a lifting sheave or set of sheaves, means adapted to automatically throw off the differential power and allow the use of the lifting sheave or sheaves as a direct simple pulley, and means whereby the load may he held suspended at any point when the differential power is so thrown 0E, substantially as specified.

In a pulley-block, in combination, a differential-gear operating-wheel, a lifting sheave or set of sheaves, means adapted to automatically throw off the differential power and allow the use of the lifting sheave or sheaves as a direct simple pulley, and means for braking the said lifting sheave or sheaves, substantially as specified.

4. In a pulley-block, in combination, a differential gear operating wheel, a lifting sheave or set of sheaves, means adapted to automatically throw off the differential power and allow the use of the lifting sheave or sheaves as a direct simple pulley, means whereby the load may be held suspended at any point when the differential power is so thrown off, and means for braking the said lifting sheave or sheaves, substantially as specified.

5. In a pulley-block, in combination, a differential gear operating wheel, a lifting sheave or set of sheaves, and a ratchet and pawl adapted to automatically throw off the differential power and allow the use of the lifting sheave or sheaves as a direct simple pulley, substantially as specified.

6. In a pulley-block, in combination, a differential gear operatingwheel, a lifting sheave or set of sheaves, a ratchet and pawl adapted to automatically throw off the differential power and allow the use of the lifting sheave or sheaves as a direct simple pulley, and means for braking said lifting sheave or sheaves, substantially as specified.

7. In a pulley-block, in combination, adifferential gear operating wheel, a lifting sheave or set of sheaves, a ratchet and pawl adapted to automatically throw off the differential power and allow the use of the lifting sheave or sheaves as a direct simple pulley, and means adapted to lock said pawl in said ratchet until said ratchet is given aslight reverse impulse, substantially as specified.

8. In a pulley-block, in combination, a differential gear operating wheel, a lifting sheave or set of sheaves, a ratchet and pawl adapted to automatically throw off the difierential power and allow the use of the lifting sheave or sheaves as a direct simple pulley, means adapted to lock said pawl in said ratchet until said ratchet is given a slight re- IIO verse impulse, and means for braking said lifting sheave or sheaves, substantially as specified.

9. In a pulley-block, in combination, a differential-gear operating-wheel, a chain-pocketed lifting-sheave,accessory unpocketed lifting-sheaves, and a ratchet and pawl, the said -ratchet being secured to a gear meshing with one side of the aforesaid differential gearing, substantially as specified.

10. In a pulley-block, in combination, a differential-gear operating-wheel, a chain-pocketed lifting-sheave, accessory un pocketed liftin g sheaves, a ratchet and pawl, the said ratchet being secured to a gear meshing with one side of the aforesaid differential gearing, a friction-wheel secured to one of the lifting sheaves, and a band-brake bearing upon said friction-wheel, substantially'as specified.

11. In a pulley-block, in combination, a differential-gear operating-wheel, a chain-pocketed lifting-sheave',accessory unpocketed liftin g sheaves, a ratchet and pawl, the said ratchet being secured to a gear meshing with one side of the aforesaid differential gearing,

one of the lifting-sheaves, and a band-brake bearing upon said friction-wheel, substantially as specified.

13 In a differentialpower pulley-block, means adapted to automatically throw off the differential power and allow the use of the lifting sheave or sheaves as adirect simple pulley.

. RICHARD LAVERY. Witnesses:

HENRY LOVE CLARKE, GEO. L. LAVERY.

reverse impulse, a friction-wheel secured to 

